The purpose of this project is to examine the subcellular and extracellular structure of nerve and muscle and relate such structure to function. Electron microscopy, protein chemistry, structural modeling, physical chemistry and electrophysiological methods are employed. The following structures are probed: 1) Cytoskeleton, 2) Neurofilaments, 3) microtubules, 4) Schwann sheath, 5) Schwann cells, 6) Endoneurium. The Schwann sheath and generalized neuronal packing are modeled.